kingdom plantae chapters 22-25. what plants need to survive minerals, gas exchange, and movement of...
TRANSCRIPT
What Plants Need to Survive
• •
• Minerals, gas exchange, and movement of materials
• alternation of generations—one generation produces spores and other produces gametes
•Plants evolved from ancestors of modernalgae
• When moved onto land had to evolve structures to acquire, transport, and conserve water.• Also had to be able to reproduce sexually
Floweringplants
Cone-bearingplants
Ferns andtheir relatives
Mosses andtheir relatives
Green algaeancestor
Flowers; SeedsEnclosed in Fruit
Seeds
Water-Conducting(Vascular) Tissue
Evolution of Plants
Floweringplants235,000 species
Cone-bearing plants760 species
Ferns andtheir relatives11,000 species
Mosses andtheir relatives15,600 species
Diversity of Plants
Nonvascular Plants/ Bryophytes • ex-mosses, hornworts, liverworts• rhizoids-present instead of true roots --anchor plants to ground AND absorb water and minerals from soil by osmosis---no transport system for moving water and minerals.• low-growing, found in moist and shaded areas• can tolerate harsh environments
Vascular Plants:
Ferns, Gymnosperms,
and Angiosperms1. specialized vascular tissues to
transport water, minerals, and nutrients—two
types • Phloem—conducts sugars away
from leaves and stems
• Xylem---transport water and minerals
from roots to other parts of plant
2. Leaf-structure that carries out most photosynthesis
-contains vascular tissue in the form of veins
3. cuticle-waxy protective covering on leaves and stems
--impermeable to water and gases required by plant
5. Guard cells-border each stomate and control its size by expanding and contracting at proper times.
Guard Cells
Open Stomate Closed Stomate
6. Roots-organ that absorbs water and minerals from soil, transports them to stem, & anchors plant into ground.
• actively growing portion of root is coveredby a root cap• root hairs-increase the surface area for water and nutrient uptake
7. Stem-structural support for upright growth and transport of materials
Types of stems1. Herbaceous-flexible, soft, usually green2. Woody-stiff, nongreen, contain layersof wood.
Seedless Vascular Plants• ex-ferns, horsetails, clubmosses•reproduce asexually by forming spores on underside of leaves --spores found in sporangia• Next phase, Sexual reproduction, requires water
--sperm swim to eggs• highly divided leaves called fronds
Seed Plants• Adaptations that allow plants to reproduce without water
1. Flowers or cones-gametes grow within these
2. Transfer of sperm by pollination3. Seeds that house embryo
• Seed-contains zygote/embryo, food supply (endosperm), and protective coat (seed coat) to prevent drying out
Seed coat
embryo
Food supply
Seeds Continued• Allow offspring of plants to be dispersed to new locations-by wind, water, animals
• dormant stage of plant life cycle
• germination-early growth stage of plant embryo--occurs when conditions are right for growth (moisture and temperature)
Pollen• contains the male gamete (sperm)
• pollination-pollen grain is carried to egg-by1. Wind 2. Water3. Animals
Gymnosperms• gymnos=naked sperma=seed• First group to have seeds
• most gymnosperms are conifers- seeds are produced in cones
-ex-cedar, cypress, pine, & spruce
• Needle-like leaves--shape is an adaptation to reduce
surface area over which water is lost to evaporation• female and male cones—most are wind pollinated where pollen is carried by wind from male cone to female cone• adapted to cold climates-thick cuticle• retain leaves year-round=evergreen
Angiosperms• Flowering plants
• seed found within fruit
• Flower-reproductive structure• brightly colored or heavily scented toattract pollinators that carry pollen from one flower to another
-more direct than wind pollination
Flower Parts
Sepals-modified leaves
-male flower part-Stamen
Filament
Pg. 612
Anther
Carpel-female flower part
Petal
ovule
ovary
stigmastyle
• Stamen-male • made of
1. Anther-pollen-containing sac2. Filament-stalk of stamen
• Pistil/Carpel-female• made of
1. Style-stalk of pistil2. Stigma-sticky tip of style3. Ovary-swollen lower portion
-ovules-inside ovary
•Fruit• made of ovary with thickened wallsthat contains one or more seeds andother flower parts • adaptation for seed dispersal
-when animals eat fruit and thendefecate, seeds are passed
-THIS IS THE REASON FRUITS EXIST • many vegetables are fruits
• Cotyledon-seed leaves of embryo• store food
Monocots Dicots
Seeds
Leaves
Flowers
Stems
Roots
Single cotyledon
Parallel veins
Floral parts often in multiples of 3
Vascularbundlesscattered throughout stem
Fibrous roots
Two cotyledons
Branched veins
Floral parts often in multiplesof 4 or 5
Vascularbundlesarranged ina ring
Taproot
Section 22-5
Figure 22–25 Comparison ofMonocots and Dicots
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Plant adaptations• aquatic• carnivorous • halophytes• desert plants• epiphytes• chemical defenses
Uses ofPlants• food, medicine,wood, rubber, clothing, etc.